.left {
    width: 100%;
    height: 100%;
    background: #f4f4f4;
    overflow-x: hidden;
    font-size: 15px;
    ul {
        li {
            width: 80%;
            height: 40px;
            line-height: 40px;
            text-align: center;
            border-radius: 5px 5px 5px 5px;
        }
        a {
            text-decoration: none;
        }
        li:hover {
            background: #bfd4ef;
        }
    }
}